Greg's Wade extruder for Prusa i3 Vanilla

It fits the standard x-carriage of Prusa i3 Vanilla repo.
I also added a few pieces that help to avoid warping (using no brim), easy to remove.
There's also a spacer useful if you use standard NEMA17 4.8 kg/cm motors to increase the distance from the frame to the motor itself.

Based on misan's Greg Extruder (use his gears and idler/washer)